Huffa

Got it tuned today, all went well. Its a conservative tune, plenty of fuel and not a lot of timing but is going well. I have a weekend of racing only just over a week away so just need to do some driving and get a handle of how the hull sits on the water. Stoked to have it going, 7-8psi boost, heres a quick clip of it running on the trailer,thats the best I could do for now as was on my own once tuner left.

SethU

That's so great. Good to hear of the progress. Very conservative on the boost too.

With 7-8psi, intercooled, on 98 octane... there's a lot left on the table. What's your impression so far?

What is your peak rpm at this point?

Huffa

Yes happy with how its going for a starting point. I probably made a mistake of choosing to run with a big blade in the unit that the boat ran with the injected big block. Its pulling that blade to 5300rpm. Maybe I should have installed my other blade that is a bit finer and it would have let it rev a bit more, but I was concerned that the fine blade was going to rev too much and didn't want to be sitting on 6000rpm all day on a stock engine. I cant just change blades and try because its only tuned up to that 5300rpm, so if I change blade more tuning needs to be done and I have 2 days racing this weekend, just need it to hold together for the 100miles of racing. Had a play yesterday.

Forcefed86

iTrader: (4)

Whats the top speed as it sits? How much do you think you have in it total minus the engine/turbo parts? Basically the equivalent of a "roller" (do they calls them "floaters" in the boat world? ) Looks like fun!

SethU

I'm not super familiar with Legend Pumps. Are the impellers interchangeable with Berkeley drives? Something I read eluded to this, but a search for a definitive answer was fruitless.

Huffa

Gave up counting way back. Yes Berkeley blade fits into the legend unit, getting about 86-87mph at the moment.

SethU

Looking at the impeller chart and taking into account the previous engine... I assume you have an "A" cut impeller, which puts your current power roughly at 450hp





6000 rpm will put you close to 700hp with that impeller. Which, the engine may make/pull when you turn the boost up. However, with your cam, you'll still be +/-1000 rpm short of where it will most likely make peak HP. If it doesn't pull 6000 with 15-20psi, I'd consider camming down a bit, for the intended rpm. Or if you don't mind spinning it higher... if I recall correctly, a similar engine build (slightly smaller cam) pulled a "C" cut impeller (again, IIRC) past 7300... 900hp range, 16psi... Drag boat though. Don't think he ever laid into it for more than seconds at a time, let alone the hour your looking at.

Or... if you like what it does, leave it alone and run the **** out of it, as is.

Would love more video!

Huffa

The blade was measured up and would be closer to an AA, was told it would need 750-800hp to get it to 5800-6000rpm.

SethU

Oh, nice. I was under the impression we didn't really know what was in there. Yup, 800 at 6k. I don't think your engine would pull that at that RPM. However, it indicates you're over the 500 mark at only 5300... That's impressive given you're probably closer to peak TQ than peak HP in the rpm band. Now I'm curious what it'll pull this one to with some more boost. Do you know what cut the other impeller is?

Hope all goes well and look forward to hearing race results and how everything holds up.

Huffa

Thanks for that. I think the other blade is about an AB. Should have run with that but too late now. Yea hope the 5.3 can hold together for the weekend, I am expecting anything! Wont be trying to break any records, just to complete the two days would be nice and get to grips with driving the tunnel. Let you know how we get on.

Tomhames

iTrader: (3)

Nice! Boat looks great- please share some video of it in action at the races!

Huffa

Early finish to my weekend, 3/4 of the way up the first leg the 5.3 lost a couple pounds boost then went off song followed by falling oil pressure and blowing oil out breathers and a knocking noise. Parked it up and got a tow upstream to where we got the trailer to it. Wont know for sure whats happened until I pull it down. Dam!

SethU

Damn damn, double damn-it!

Not wanting to reread through the thread... you did open your ring gaps didn't you?

Were you running a data log you can review?

Really sorry to hear the poor news Huffa. Out of curiosity, how well did she do up to that point? Holding her own?

Huffa

Thanks for that. No, due to lack of time we never opened up the ring gaps. I knew that was a gamble. I pulled plugs yesterday, nothing obvious there I don't think. I did compression test, one cylinder @ 165, one cylinder @ 180 and the rest 170-175. I was expecting to find a cylinder with zero or very little due to the oil that blew out the breathers. I don't run any sort of data log. Yes it was going well up to that point. Just have to get it out and pull it down. I did take the advice and change the air filters to K&N with no little bits in them that could fall off like the cheapies!

Huffa

Wanted to ask, could my 5.3 have any major issues with oil return from heads running at a constant 5300rpm under boost? I was just wondering if the oil that was pushed out from breathers which are on tall stacks could have actually been because the top of the heads were full of oil and therefore caused a decline in oil pressure and lead to bearing failure. The engine runs a good sized water cooled oil cooler which is mounted up behind the drivers seat. With that cooler in the system it took 9 litres of oil to get it up to the full mark on the dipstick which was a good amount, but I wonder how much oil is lost to the system and heads under constant thrashing? I haven't pulled the engine out yet as waiting to get my engine stand back, but the knocking and oil pressure loss points to a bearing. Any ideas?

coltboostin

Oiling systems in these motors are not optimal for what your where doing.

Try ans source a used dry sump system when you put it back together or consider making a deep pan and making external oil drains for the heads in the rear of the motor.

SethU

FWIW, there's a guy running twin factory stock aluminum 5.3's on the stock computers, in a 24' Skater. Bravo outdrives.

IIRC, he's not a stranger to extended 10+ minute runs, wide open throttle, pulling 6200 rpm, 200 over the rev limiter.

Two engines. 6200rpm. 10+ minutes. Regularly.

Granted there are differences in the application and power levels, as far as oil stacking up in the heads and starving the engine of oil... seems to be evidence to the contrary. A singular (or two if you want to look at it that way) internet story and nothing more. Just something to take into consideration, food for thought.

My speculation on the failure... Probably broke a ringland, increased blowby, increased crankcase windage, or simply blew enough oil out... may still hold fair compression under compression test conditions. But, we'll just have to wait for the autopsy and see what there is to see then.

As a start, I might pull the turbos, remove the turbine housings, and inspect the turbine blades for damage... if it were me. You did mention a slight loss of boost.

Maybe pull the intake and look for any evidence there too. Piston pieces anywhere? Rattling around in the manifold or in any of the intake ports?

Pull the heads. Don't need the engine out of the boat to get it down to a short block.

Huffa

Got the 5.3 out and pulled it down. Its spun a centre main bearing, gudgeons are seized, bores, pistons and rings are fine. Its had a severe case of oil starvation. All bearings especially cam bearings showing signs of lack of oil, timing chain dry as a chip. Still had plenty of oil in the sump and cooler. So whats caused it? Faulty oil pump? Standard oil pump not up to the job to feed big oil cooler and turbos?

stevieturbo

Detail the oiling system ? Or is it all stock ?

What oil pan etc, how much oil in it ? What oil ? what oil pressure did it have etc etc ?

Forcefed86

iTrader: (4)

Details on the oiling system would help alot... What kinda angle does the engine sit at when you're "up on a plane" or whatever you call it...? OEM pump should easily be up to the task at 5300 RPM.

I'd get a pressure sensor on it right away so you can log oil pressure. Well worth the $16 sensor...

http://www.ebay.com/itm/Pressure-tra...5WU8Cs&vxp=mtr